A Move Deleter (Japanese: わすれオヤジForgetting Man) is a person who, for no charge, will make a Pokémon forget a move it knows. They are the counterparts to the Move Reminder, often found in the same location.

Uses

A Move Deleter's only restrictions are that they cannot make a Pokémon forget the last move it knows and, in Pokémon Emerald, they cannot make a Pokémon forget Surf if that Pokémon is the only one in the player's party or PC that knows the move.

Those restrictions aside, the Move Deleter is the only way for a Pokémon to forget HM moves such as Cut or Fly besides exploiting the Day Care. This is particularly useful for transferring Pokémon from Generations III or IV to the following generation via Pal Park or Poké Transfer, since Pokémon cannot know any HM moves when they are transferred.

The Move Deleter's service was likewise useful in the Generation II games to delete moves exclusive to the second generation so that Pokémon could be traded to Generation I games via the Time Capsule.

In Pokémon XD, the Move Deleter is also responsible for helping Michael with an issue involving the Move Reminder, who is also located at Mt. Battle with the latter: if any of his Pokémon already have four move slots occupied, then the Move Reminder cannot reteach the Pokémon a forgotten move unless the Move Deleter helps to erase a move. Unlike the Move Reminder, the Deleter's service is free of charge.

Quotes

Pokémon Gold, Silver, and Crystal

"Umm… Oh, yes, I'm the Move Deleter. I can make Pokémon forget moves. Shall I make a Pokémon forget?"

No:"No? Come visit me again."

Yes:"Which Pokémon?"

If the selected Pokémon only knows one move:

"That Pokémon knows only one move."

If the selected Pokémon knows more than one move:

"Which move should it forget, then?" (After choosing a move:) "Oh, make it forget <move>?"

No:"No? Come visit me again."

Yes:"Done! Your Pokémon forgot the move."

Pokémon Ruby, Sapphire, and Emerald

"Uh... Oh, yes, I'm the Move Deleter. I can make Pokémon forget their moves. Would you like me to do that?"

No:"Come again if there are moves that need to be forgotten."

Yes:"Which Pokémon should forget a move?"

If the selected Pokémon only knows one move:

"<Pokémon> knows only one move so it can't be forgotten…"

If the selected Pokémon knows more than one move:

"Which move should be forgotten?" (After choosing a move:) "Hm! <Pokémon>'s <move>? That move should be forgotten?"

No:"Come again if there are moves that need to be forgotten."

Yes:

In Emerald, if the move is Surf and the Pokémon is the last one that knows it:

"Hm! Your <Pokémon> doesn't seem willing to forget Surf.

Otherwise:

"It worked to perfection! <Pokémon> has forgotten <move> completely."

Pokémon FireRed and LeafGreen

"Umm... Oh, yes, I'm the Move Deleter. I can make Pokémon forget their moves. Would you like me to do that?"

No:"Come again if there are other moves to be forgotten."

Yes:"Which Pokémon should forget a move?"

If the selected Pokémon only knows one move:

"<Pokémon> seems to know only one move…"

If the selected Pokémon knows more than one move:

"Which move should be forgotten?" (After choosing a move:) "Hm! <Pokémon>'s <move>? That move should be forgotten?"

No:"Come again if there are other moves to be forgotten."

Yes:"It worked to perfection! <Pokémon> has forgotten <move> completely."

Pokémon Colosseum

(if talked to before defeating Dakim)

"This is a distinguished place of training for honorable trainers! What is the meaning of this outrage? Those attackers... how dare they attack others without any regard for the rules? They're failure as trainers! But anyway... Uh... Oh, yes, I'm the Move Deleter. Don't be shocked, but... I can make Pokémon forget their moves. Would you like me to do that?"

(if talked to after defeating Dakim but before the first Mt. Battle challenge)

"Good, good! Well done, you, a trainer whose heart is just and pure! Stay on the path of the just and good. But that's that, and this is this. Uh... Oh, yes, I'm the Move Deleter. Don't be shocked, but... I can make Pokémon forget their moves. Would you like me to do that?"

(if talked to after the first Mt. Battle challenge)

"Ah, you two! You've come for the Mt. Battle challenge? Very impressive! But anyways... Uh... Oh, yes, I'm the Move Deleter. Don't be shocked, but... I can make Pokémon forget their moves. Would you like me to do that?"

No: "Come again if there are other moves to be forgotten."

Yes: "Which Pokémon should I make forget a move?"

If a Shadow Pokémon is selected:

"Hmmm... I'm sorry to disappoint you, but there's nothing that I can do for this Pokémon. Would you like me to make a different Pokémon forget a move or two?"

If the selected Pokémon only knows one move:

"<Nickname> seems to know only one move. Would you like me to make a different Pokémon forget a move or two?"

If the selected Pokémon knows more than one move (after choosing a move):

"Hm! <Nickname>'s <move>? That move should be forgotten?"

No: "All right. Which move should be forgotten?"

Yes: "It worked to perfection! <Nickname> has forgotten <move> completely."

"Are there any other moves to be forgotten?"

No: "Come again if there are other moves to be forgotten."

Yes: (opens move list)

Pokémon XD: Gale of Darkness

"My name is the Move Deleter. Like my name suggests, I can make Pokémon forget their moves. Well, lad? Should I make your Pokémon forget any moves?"

No: "Come see me if you would like any of your Pokémon to unlearn moves."

Yes: "Which Pokémon should I make forget one or more moves?"

If a Shadow Pokémon is selected:

"Hmm... I'm sorry, lad, but that Pokémon is too much for me to handle. Should I make a different Pokémon unlearn its moves?"

If the selected Pokémon only knows one move:

"Hmm... Your <nickname> seems to know only one move. I can't make it unlearn that. Should I make a different Pokémon unlearn its moves?"

If the selected Pokémon knows more than one move:

"Fine. Now, which move should be deleted?" (After choosing a move:) "Hmhm. Your <nickname>'s <move> should be forgotten?"

No: "Fine. Now which move should be deleted?"

Yes: "There! A clean sweep! Your <nickname> has completely forgotten how to use <move>."

"Would you like it to forget any other move?"

No: "Come see me if you would like any of your Pokémon to unlearn moves."

Pokémon Omega Ruby and Alpha Sapphire

"Uh… Oh yes! I'm the Move Deleter! I can make Pokémon forget their moves."

After his intro or when the player speaks to him subsequently:

"You're here so I can make your Pokémon forget a move, um-hmm?"

No:"Remember me if there are moves you need to, um, have forgotten!"

Yes:"Which Pokémon will that be, hmm?"

If an Egg is selected:

"Hrmmp? I'm fairly certain that, um, Egg doesn't know any moves."

If the selected Pokémon only knows one move:

"Um, that Pokémon only knows one move. Hrmmp, I can't make it forget its only move..."

If the selected Pokémon knows more than one move:

"Which move do you want forgotten, hrmmp?"

After choosing a move:

"Charming! It worked perfectly! Your Pokémon has completely forgotten how to use <move>!"

Pokémon Sun and Moon

When the player first* speaks to him:

"Uh... Now who was I again? ... ... ... ... ... ... Oh yes! I'm the Move Deleter! I can make Pokémon forget their moves."

After his intro or when the player speaks to him subsequently:

"You're here so I can make your Pokémon forget a move, um-hmm?"

No:"Just remember me when there's something you want to forget!"

Yes:"Which Pokémon would that be?"

If the selected Pokémon only knows one move:

"What's that, friend? That Pokémon only knows one move, you know?"

If the selected Pokémon knows more than one move:

"Mm-hmm... And which move should it forget?"

After choosing a move:

"It was a great success! Your Pokémon has forgotten that it ever even knew <move>!"

Trivia

All of the Move Deleters, excluding the one in Pokémon XD: Gale of Darkness, are characteristically forgetful (some even temporarily forgetting who they are), which is a reference to their Japanese name.